I grew up in a county of 25,000 people. Some of the kids I went to school with could tell you who everybody's fourth or fifth cousins were. This is how you deal with a small marriage market if you are religious and picky about a spouse not being your second or third cousin. You know your gene pool. In big cities, people assume that everybody is a stranger and "no relation", although in the real world, this is not certain. You don't hear about people accidentally marrying their sister in small towns or rural counties.

In much of the world, first and second cousin marriages are common. It doesn't usually do a lot of genetic damage unless you inbreed for eight to nine generations. It's still possible to have genetic tares show up immediately, which is why incest is taboo, however kinship is defined. In some societies, it is not necessarily defined by descent. People may be sorted out into "tribes" or "clans" and some of your blood relations will be in the same clan, some in different clans.

I said that my native county has 25,000 people, but the genealogy of the most common family contains 8,000 people or so. I have numerous relations in this family. I'd have to be careful marrying into that one family because they are perhaps one quarter of all the people in the County. The next largest family is probably about 1,000, and so forth: this sort of thing obeys a "power law" and the numbers drop off fast in the first few data points.

The original founding population of Iceland was a few thousand individuals (many of whom married four or five times because spouses kept dying--the average Victorian marriage in the US, Canada, etc., lasted 11 years, which means that it was easier to tough out a bad marriage without divorcing. You knew that one of you was likely to die soon enough.) In Iceland, lives were harder and shorter than Victorian England, let us say. Thus the slots in the ole family tree fill up pretty fast with the same persons showing up in more than one slot.

This phenomenon is called "pedigree collapse". It is universal but you might not notice if you are ignorant of your family tree or are a city slicker whose ancestors are usually not closely related.

Two of my grand-parents are third cousins to each other. That's because of that 25,000 upper limit on the county population during their lifetimes. When the population was smaller, you find people marrying first cousins (the children of their aunts and uncles). You find whole families of daughters marrying whole families of sons like in the book and movie Seven Wives for Seven Brothers, which is based on historioc events in a small county of Ontario, the one that John Kenneth Galbraith hails from, in fact.

Of course, this sort of thing is OK if it happens among pioneers in a rapidly growing community. By the time all the first cousins are old enough to marry, they may have somebody to marry who isn't a first cousin.

But you can see why Icelanders have a hard time finding spouses without going abroad or importing them.

The original breeding population of French Canada is about 10,000 couples, or 5,000 men, 5,000 women.

These often divorced and re-married because the market was so tight they'd grab the first creature with two legs and then decide they could get a better offer. It didn't help that many of the women were filles du Roy, which is to say the daughters of deceased or impoverished officers in the armies of King Louis XIV. They were NOT, NOT, NOT, filles de joie as some vicious or mal-informed English language historians would have you believe. They were young ladies of good family but reduced circumstances. Picky, perhaps, but not hookers. And there is a very simple proof of this: in those days a hooker would be sterile within two years of beginning her trade because of untreated syphilis. There were no antibiotics.

The policy of the State (AKA Louis XIV) was to increase the population in France and the colonies, and he paid baby bounties and marriage bounties to do it. The filles du Roi were well-endowed--with a purse of monies and other benefits. The single man was harassed and fined until he gave in and either ran to the High Country, to live free and unmarried with the Indians, or married and began a long line of children.

If you think Louis XIV and his Ministers of State were ignorant of venereal disease and stupid enough to pack off whores to the colonies to marry honest hard-working colonists, many of them noble adventurers, then you need a kick in the head from a horse to wise you up.

Whores don't make good wives for colonists who were expected to breed fast and breed long. The birth rate in New France was higher than the birth rate in Old France, 6.5 children per woman to 6 children per woman. There was a lot of room, fish and game were plentiful, and the climate was bracing but healthy. The population was strung out along the river bank so disease traveled slowly. I am descended from ten couples who had more than 1,000 descendants EACH by the Census 1729 or thereabouts. That's about 10,000 children right there.

Looking at the other side of my family tree (the New Englanders mostly, also the New York and New Jersey Dutch, and other British colonists from Nova Scotia to Georgia), you seem the same pattern of expansionism pushed with more boot-strapy and less gubbermint monies, but not entirely so. The New England townships were basically business partnerships, and the partners made sure that any new residents were the right sort. Which is to say the right race, religion, and attitude. They were really hard on Catholics, Jews, other Protestants, and the irreligious. They were also hard on men who couldn't do a hard day's work and turn a plot of woods into a thriving farm full of hard-working snot-nosed Puritan brats.

So it worked out the same whether the Government or the notables of the town chose who to give land to, who to support, who to allow into their Church, their community and their homes.

New England and New France were about as productive (in work, goods, services, and children) as each other, disproving the thesis that there is such a thing as Protestant Work Ethic. There is a lower middle class and upper working class work ethic. Everybody else prefers to live off of the labour of others, especially the rich who loot us all through sharp business, shady commerce, outright theft, and legal plunder as Fréderick Bastiat calls it in The Law, which I am still reading.

The dishonest rich take care of the plundering through crime and the honest rich take care plundering through Church, Media, and State, AKA the Military-Industrial-Media Complex. But I digress.

Back to our comely cousins in Shelbyville, er, Sheeple, I mean Sheep. Yeah, that's the ticket, back to our sheep!